How to keep cakes with no frosting on side from drying out?

I've seen several cakes that have no frosting on the sides - such as Sweetapolita's Inside-Out Neapolitan Layer Cake. Is there something you do to keep the cake layers from drying out since there is no frosting covering the side?

Another idea... keep the layers tightly wrapped and don't fill and frost until close to serving time. After the event, just frost the sides. Or you can put plastic wrap around it similar to putting it on the cut sides. This won't look good, but both ideas will preserve it if it's just for personal use after an event.